float_6969’s Official CA18DET upgrade guide

Well I think our little CA section has finally grown large enough that I would like to start to create a generic upgrade guide to direct our new members towards so that they have direction with their upgrades on the CA.

As we all know (or you will soon know when you get your CA), stock is NEVER good enough!

All comments, corrections, and additions will be welcomed and encouraged. A link to this thread will be posted in the main sticky at the top of the forum and all comments will be consolidated into this main post on the thread.

From my experience, this is the safest, and most logical upgrade route. It’s by no means the gospel, but is founded from years of participation in this forum and seeing the trial and error of others and my own.

I am going to keep this engine related as much as possible. Everything else that isn’t CA specific doesn’t really need to be talked about in this particular part of the forum, ie.,suspension, drivetrain, electrical, body, ect.

So here goes…
Pre-swap Mods
-These are things that can be done before you ever even get your CA and will help to have your chassis ready for the new turbo motor later on down the road.
A. The Radiator: radiator that comes in your car is probably over 10 years old and wasn’t really designed for the cooling demands of a turbo motor. Often times a new single core radiator with a higher pressure cap and electric fans is plenty enough. If you do install a new radiator, flush the system really well before installing the new core.
B.Oil Cooler: Oil coolers are often overlooked but shouldn’t be. The EDM CA’s all had oil coolers stock (though crappy) and I think for good reason. This is another modification that can be applied to the KA and swapped over to the CA with little issue when it comes swap time.
C.Gauges: A boost gauge is a must. People will rag on me for this, but I would also say a narrow-band AFR gauge. NO! They’re not accurate! But they’re better than nothing and way cheaper than a wide-band. An oil pressure gauge is also very nice to have as the idot light on the dash will generally tell you after it’s already too late. And lastly a fuel pressure gauge, as you will need this to adjust your fuel pressure with the aftermarket FPR needed with the walbro that you will want to install when you actually get the CA.
D.Ground Wire Kit: This is optional, but certainly helpful. Once again this can generally be converted over to the new motor later on down the road. This will reduce the stress and noise in the electrical system. It may free up a tiny bit of HP because the alternator won’t have to work as hard, but it will also give the ECU more accurate info from it’s various sensors and help to smooth out the idle.

1. Good condition CA.
-I start here because if your motor is in poor condition, you’ll want to rebuild it and I’m not going to go into detail on that in this thread. This includes the replacement of all of the major gaskets, seals, vacuum lines, coolant lines, and the water pump. USE THE WATER PUMP FROM A 1984 NISSAN 200SX TURBO (S12 W/CA18ET)!!!

2.Clutch and Engine and Transmission mounts.
-You will want to install these as well as mods 3 and 4 before actually installing the motor in the car. It is much easier to do them now, than later. For the clutch you’ve only got one dedicated CA option in the USA and that is from SPEC. BUT you can also use any KA clutch that you would like by simply removing the alignment pins form the flywheel.
-Remember to use CA specific motor mounts so that the motor will sit properly in the engine bay. The regular S13 transmission mount will work fine. Here are the NISMO part numbers;
11210-RS520
11220-RS520(IDK which is left or right, but which ever is shorter goes on the exhaust side of the motor.)
11320-RS541 (trans mount)

3. Fuel pump and FPR (Fuel Pressure Regulator).
-I put these together because they need done at the same time and preferably before you install the motor. The fuel pump because the stock pump isn’t good for much past 200hp IIRC (someone correct me if I’m wrong with that figure), and the regulator because the walbro unit that most people use over runs the stock FPR, so you will need an after-market, adjustable unit to be able to turn the fuel pressure back down to stock. Click here for more FPR info

4. KA24DE Throttle Body.
-This TB will bolt right up to the stock plenum. Once again you will want to do this before you actually install the motor. You will need to remove the plenum to do this as you will want to match the plenum’s inlet to the TB’s diameter. A dremel with a Carbide bit will make short work of the aluminum on the manifol. Use some sort of fine grinding stone afterwards to smooth it out. You will also want to swap the pulley from the CA over to the KA TB.

5. Cone Air Filter or Modded Stock air box if you have it.
-A lot of people don’t get the stock air box, so you will be forced to get a cone air filter anyway. If you did get the stock box, there isn’t anything wrong with it, just simply cut open the bottom of the box to increase flow the air filter element.
-Cold air is better air. This applies to turbos just the same as it does NA cars. Some may argue, but they’re wrong! Shielding engine bay heat from the intake or some sort of cold air ducting will help tremendously.

6. Hard Suction Pipe.
-Some may question this and think it’s just for looks, but I hate the stock rubber intake piece. That stupid metal coil (necessary so the rubber doesn’t collapse) and all of the ridges just make the turbo work harder. It’s also a must if you want to recirculate your BOV. Apex Z32 Suction kit from Phase2 Motorsports

7. BOV or Recirculation Valve.
-The CA lacks any sort of recirculation valve or BOV in stock form. At lower boost levels this isn’t too big of a deal, but still hard on the turbo. With the CA’s MAFS setup, using an atmospheric BOV may or may not cause problems. It’s hit or miss and entirely up to you. If you got the hard suction pipe I mentioned above, recirculation shouldn’t be too big of a deal.

8. Intercooler.
-The stock side mount is crap. Plain and simple. For anything more than stock boost it’s too small. Also, unless you properly install air ducting to guide the flow of air into and out of the sidemount, it’s doing little for you. In it’s stock form, there was an opening in the front bumper. But it’s more complicated than that. There was a formed plastic tube that tightly sealed against the bumper and the intercooler. When driving this creates a high pressure area infront of the intercooler. Behind the intercooler, in the splash gaurd of the wheel well were vents to allow the hot air that just passed through the intercooler to escape into the low pressure area of the wheel well. With out this setup the stock sidemount isn’t NEARLY as effective as it should be. I won’t necessarily say that you need a FMIC, but something, bigger and better than the stock unit, at least to point. I can talk all day about intercooler theory and the physics behind it. But why not let Corky Bell do the work for me? CLICK HERE TO LEARN ABOUT INTERCOOLERS

9. Exhaust.
-I’m not going to break this down into individual sections, but with a turbocharged motor, bigger is better, but as always, also louder. For the sake of simplicity I won’t get into the physics of why this is true. Most start with a Cat-Back system, then replace the down-pipe, and then the O2 pipe. Ideally they are done all at once, but eventually you’ll want to replace all of it. Please, please,please, don’t get rid of the catylitic converter! A high flow unit isn’t that expensive, and will cost you little noticeable horsepower. Remember, the air you pollute today is simply being borrowed from tommorrows children. [/rant]

10. ECU, MAFS, Injectors, and SAFC (or something like it).
-Unfortunately, you kinda have to do all of these together. Some will say that the ECU doesn’t need re-chipped, that the whole purpose of the SAFC is to accommodate the MAFS and Injectors. This approach is OK, up to a certain extent. The problem is that the SAFC basically lies to the ECU to get the correct fuel amounts. This can cause very odd, and bad timing to be applied to the motor. The SAFC should be treated as a fine tune for a re-chipped ECU. Get your injectors, and MAFS, and have the ECU tuned for them. Then install the SAFC, go to the dyno, and fine tune the fuel curve.

11. Boost controller.
-Some may wonder why I have this so far down the list. I do this because it’s the safest way to do it. The stock turbo really is worthless past 14psi, and with the addition of the 3″ exhaust you should be up around 10psi on the stock waste-gate actuator. I can tell you from experience that turning the boost up from 10psi to 14psi on the stock CA T25 will yield you a whopping 10RWHP and a whole lot of hot air going into your motor. Which leads me to my next mod….

12. Bigger turbo (Turbo manifold).
-There are a lot of options at this point, but I’ll list a few of the more common ones.
A. The SR T25 is a decent upgrade and will easily help you to break the 200RWHP mark. Keep the boost below 14psi again with this turbo, but it should now get you another 20-30hp as this boost level as opposed to the CA T25 at this boost level.
B. For most, the next step up is a T28 of some sort. This turbo is good to about 18psi on our cars and should get you near 270RWHP. With this turbo and power level it may not hurt to go to a tubular equal length manifold.
C. T3/T4 hybrid or beyond. A turbo manifold is a must and if you don’t know how to do this, then you shouldn’t be doing it!

At this point you’ve pretty much exhausted your bolt on abilities. We could talk about cams, internals, port matching and polishing (AKA-gas flowing the heads), and standalone, but it would be pointless, as at that point it’s all circumstantial. Plus a 270RWHP S13 is a pretty fast car and will at least hang with, if not spank, most of what you’ll run into on the street.

Contributed by: float_6969